Researcher Database



FacultyGraduate School of Medical Sciences Department of Bacteriology
Last Updated :2020/07/02

Researcher Profile and Settings


  • (BLANK), Nagoya University

Academic & Professional Experience

  •   2006  - 現在, Nagoya City University, Graduate School of Medical Sciences, Department of Bacteriology
  •   2003  - 2006 , The University of Maryland

Research Activities

Research Areas

  • Life sciences, Bacteriology

Published Papers

  • Prevalence of emm1 Streptococcus pyogenes having a novel type of genomic composition., Tatsuno I, Isaka M, Matsumoto M, Hasegawa T, Microbiology and immunology, 08 , Refereed
  • Instantaneous water purification by deep ultraviolet light in water waveguide: Escherichia coli bacteria disinfection, Takahiro Matsumoto, Ichiro Tatsuno, Tadao Hasegawa, Water (Switzerland), 11, 05 01 , © 2019 by the authors. The necessity of small water purification equipment has been increasing in recent years as a result of frequent natural disasters. Ultraviolet (UV) radiation treatment is an effective method for the disinfection of bacterial contaminants in water. As an emerging technology, disinfection by deep-ultraviolet light-emitting diodes (DUV-LEDs) is promising. Few studies have used the point-source characteristics of LEDs and have instead replaced mercury vapor lamps with LEDs. Here, we demonstrate the instantaneous purification of contaminated water by combining the point source characteristics of DUV-LEDs with a water waveguide (WW). The principle is based on theWW region acting as an effective DUV disinfector, whereby a high UV dose in a confined WW region can be applied to bacterial contaminants in a short period of time (around one second). We demonstrate the effect of this DUV-LEDWWdisinfection technique by showing the results of 3-log disinfection levels of water contaminated with Escherichia coli bacteria after a short treatment time. We believe that the combination of the point-source nature of DUV-LED emission, the water-waveguide effect, and a small photovoltaic cell paves the way toward environmentally friendly and emergency preparedness portable water purification equipment that instantaneously supplies clean water just before drinking.
  • Total internal reflection of deep-ultraviolet light in a water waveguide and its application to water disinfection technologies, Takahiro Matsumoto, Rika Kikojima, Tomomi Fukuoka, Ichiro Tatsuno, Tadao Hasegawa, Water (Switzerland), 11, 02 08 , © 2019 by the authors. We propose a new disinfection technology based on a novel concept involving the use of a small, deep-ultraviolet light-emitting diode (DUV-LED); the 265-nm DUV light is coupled to a running-water stream and is guided to a distant position without diffusion due to the total internal reflection of the DUV light inside the water stream. We demonstrate here the effect of the water waveguide disinfection technique by showing significant inactivation of a contaminated surface with indicator bacteria; this was verified by comparing the results of three disinfection methods: (i) disinfection with DUV light, (ii) disinfection with running water, and (iii) disinfection with the water-waveguide method. We believe that the marriage of the point-source nature of DUV-LED emission and the water-waveguide effect paves the way towards new applications such as water washing technologies that can reduce water consumption more than one order of magnitude without using additional chemicals in a simple manner.
  • Homologous role of CovRS two-component regulatory system in NAD + -glycohydrolase activity in Streptococcus dysgalactiae subsp. equisimilis as in Streptococcus pyogenes, Tadao Hasegawa, Masakado Matsumoto, Nanako Hata, Hisako Yano, Masanori Isaka, Ichiro Tatsuno, APMIS, 127, 87 - 92, 02 01 , © 2019 APMIS. Published by John Wiley & Sons Ltd Streptococcal toxic shock syndrome (STSS) is primarily caused by Streptococcus pyogenes, but it may also be caused by Streptococcus dysgalactiae subsp. equisimilis (SDSE). The analyses of S. pyogenes have revealed the important roles of NAD + -glycohydrolase (Nga) and CovR/CovS, a two-component regulatory system. We examined these factors in SDSE by analyzing mainly two isogenic SDSE strains (12-10-1 and 12-10-3) from the blood of a patient with STSS. The Nga activities were measured and the nucleotide sequences of covR and covS genes were determined. We detected one nucleotide difference between the covR gene of 12-10-1 and that of 12-10-3, and the Nga activity of 12-10-1 was approximately 6.8-fold more than that of 12-10-3. The introduction of covR of 12-10-3 into 12-10-1 significantly reduced the Nga activity, but the introduction of 12-10-1 covR into itself had only a little effect. In addition, the knockout of covR or covS of 12-10-3 remarkably increased the Nga activity. We are the first to report that strains with wild-type and mutated covR were isolated simultaneously from an SDSE STSS patient and that the CovR/CovS two-component regulatory system is involved in the Nga activity in SDSE as well as in S. pyogenes.
  • Complete genome sequence of emm1 Streptococcus pyogenes 10-85, a strain isolated from a patient with streptococcal toxic shock syndrome in Japan, Ichiro Tatsuno, Masanori Isaka, Masakado Matsumoto, Naomi Nishio, Hideyuki Matsui, Tadao Hasegawa, Microbiology Resource Announcements, 8, 01 01 , Copyright © 2019 Tatsuno et al. Here, we announce the complete genome sequence of Streptococcus pyogenes strain 10-85 (type emm1), isolated from a patient with streptococcal toxic shock syndrome (STSS). The strain lacks the genomic regions encoding SalR-SalK, a two-component regulatory system, and the adjacent type I restriction modification system.
  • Functional Predominance of msr(D), Which Is More Effective as mef(A)-Associated Than mef(E)-Associated, Over mef(A)/mef(E) in Macrolide Resistance in Streptococcus pyogenes., Tatsuno I, Isaka M, Masuno K, Hata N, Matsumoto M, Hasegawa T, Microbial drug resistance (Larchmont, N.Y.), 24, (8) 1089 - 1097, 10 , Refereed
  • Predominant role of msr(D) over mef(A) in macrolide resistance in Streptococcus pyogenes., Zhang Y, Tatsuno I, Okada R, Hata N, Matsumoto M, Isaka M, Isobe K, Hasegawa T, Microbiology (Reading, England), 162, (1) 46 - 52, 01 , Refereed
  • Relevance of the two-component sensor protein CiaH to acid and oxidative stress responses in Streptococcus pyogenes., Tatsuno I, Isaka M, Okada R, Zhang Y, Hasegawa T, BMC research notes, 7, 03 , Refereed
  • Partial loss of CovS function in Streptococcus pyogenes causes severe invasive disease., Tatsuno I, Okada R, Zhang Y, Isaka M, Hasegawa T, BMC research notes, 6, 03 , Refereed
  • Characterization of NADase-inactive NAD+ glycohydrolase in Streptococcus pyogenes., Tatsuno I, Isaka M, Hasegawa T, Advances in Microbiology, 3, (1) 91 - 100, Refereed
  • Complete nucleotide sequence of the prophage VT2-Sakai carrying the verotoxin 2 genes of the enterohemorrhagic Escherichia coli O157:H7 derived from the Sakai outbreak., Makino K, Yokoyama K, Kubota Y, Yutsudo CH, Kimura S, Kurokawa K, Ishii K, Hattori M, Tatsuno I, Abe H, Iida T, Yamamoto K, Onishi M, Hayashi T, Yasunaga T, Honda T, Sasakawa C, Shinagawa H, Genes & genetic systems, 74, (5) 227 - 239, 10 , Refereed
  • Streptococcus pyogenes protein F promotes invasion of HeLa cells., Okada N, Tatsuno I, Hanski E, Caparon M, Sasakawa C, Microbiology (Reading, England), 144 ( Pt 11), 3079 - 3086, 11 , Refereed
  • Signaling by the Escherichia coli aspartate chemoreceptor Tar with a single cytoplasmic domain per dimer., Tatsuno I, Homma M, Oosawa K, Kawagishi I, Science (New York, N.Y.), 274, (5286) 423 - 425, 10 , Refereed


  • [Adherence of enterohemorrhagic Escherichia coli O157:H7 to human epithelial cells]., Tatsuno I, Nihon saikingaku zasshi. Japanese journal of bacteriology, 62, (2) 247 - 253,   2007 05 , Refereed
  • Signal transduction across the cytoplasmic membrane by the Escherichiacoli chemoreceptors, JAPANESE JOURNAL of BACTERIOLOGY, 52, (3) 567 - 581,   1997

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